What do yo do to keep your trout tank water cool?

Do you try to cool your fish tank water? Or do you just monitor the water and maybe feed less when the temperature goes up? I've got the fish tanks in the basement so they aren't seeing the 90 degree temps we have outside right now, but the water temperature hit the 70 degree mark this week. The fish who've made it this far seem to be doing fine and are still feeding vigorously and growing. I just wondered what all you experienced trout growers do when it gets hot outside.

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I have a garden watering timer on a garden hose i have set to add water for 15 minutes three times during the hottest part of the day. Keeps tank at 60-65 with GH temps of over 100. May use more water but it keeps the fish happy. And it doesn't have the cost of a chiller. i used to send overflow to raised beds but that is dismantled now...

My water temp is still right around 70 degrees at the surface even after our recent heat wave. I have been taking quart containers of fish water, cooling them in the freezer, and then returning them to the tanks. Labor intensive, but cheaper than aquarium cooling equipment.

Here in Arizona to cool swimming pools they install sprinkler heads above the waterline and spray pool water back out over the pool's surface. The evaporative cooling effect is said to reduce the temperature of the pool. I'm not sure how much good they are in 20,000 gallons but it should make quite a difference in 500 gallons.

I have a evaporative cooler that reduces ambient air temps by 20f until the dew point gets into the 50s above that it becomes less effective. If spraying water across the surface doesn't work for you, a crude evap cooler could be created by suspending a burlap or a towel (rinse well beforehand) above the pond and pump pond water directly on it. The water that drains back into the pond will be considerably cooler. Adding a small fan will really increase the efficiency. If you want to see if it works on a personal level, dampen a wash cloth and lay it on your chest while reclined, report back how long you can keep it on your chest

That doesn't make sense. Evaporative or 'swamp' coolers chill AIR by warming the water. If the air temp is high, it is surely higher than your water and spraying it will only serve to warm your water. Everyone running a flood and drain media bed in the summer knows this first hand.

I have 2 - 1300 gallon open top tanks about 7' in diameter and 50 inches deep. I filter and circulate water at the rate of 65 gallons a minute or about 3750 gallons per hour. The tanks are loaded with 600 rainbow trout each and I will grow them out to 1.75 to 2 kilos each. They grow at a solid 1" per month. I feed them 6 times a day with automatic feeders.

This might sound dumb, but it works for moi. When the water temp begins to rise, I go down to a gas station/convenience store near by and buy bagged ice for $.99 cents a bag. I usually dump in 10 bags per tank. The ice cubes cool the water and as they melt, they add oxygen to the water.

I do the same for my Koi. They also play with the ice cubes.

As a alternative, I back flush the tank water into my catfish pond, lowering the water in my tanks by 10% and refill with my well water. My well is 220 feet deep and it is colder than my ex-wife's heart.

With my much smaller system, I was concerned that the bags of ice might introduce chloramines. Instead, I ended up taking some empty pop bottles, filling them with pond water, freezing them, and using them to cool the water. It was probably more trouble than it was worth. I think I would have been better off changing water.

Well, although that is/was my plan - use bagged ice, we have not done it yet - we are going to a variation of what you posted Tom. We bought a huge horizontal freezer off Craig'sList and we are going to freeze 2-1/2 gallon buckets of well water. Then when we need it, we get the ice pick and chip it a bit and put it in the water. But what we have done in the past is still our first defense. Lower the water level, dump it into the pond and refill the tanks with fresh well water.

Don't know if this would work (but it is what I plan on doing with my system when I get it up and running). I'm going to have a sump tank burried 4-6 feet down (where the temperature stays at a constant 50-55 degrees and has the effect of thermal cooling/heating) and have it pumped up to the surface of my fish tank that is burried half in the ground. Then i'm going to siphon the water off the bottom of my fish tank to the grow beds. My theory is... with constant 50-55 degree water pumped to the top of my fish tank and then being pulled to the bottom by the siphon effect, it will keep my whole tank the same tank year round. Do you guys think it will work?

For our smaller system of ibc fts (2/ 300 gal dedicated to trout) I plan to fill 1 gal milk jugs with water and leave them in the freezer until those few hot days we get here in Summer and just place the whole jugs into the trout ibcs. That way you can use tap water as well and no worries.

I do plan a major change in my plan to separate the trout into their own system using the uninsulated 275 buried sump (55F grnd temp)and raft beds (less heating). A bit of re-plumbing but I believe it should work. I can also add in the chest freezer cooling at that point without affecting the other fish that like it warmer in the 3/ 250 gal ibcs. Bad enough we have to balance fish and plant chemistry. Balancing temps is a whole nuther challenge. The raft crops tend to like cool temps as well. I only wish I had thought of this sooner. The media beds will be dedicated to the warmer fish breeds and warmer plant species. Now I need to bury another 275 gal sump that will be well insulated to stay warm yr round and placed in the "hothouse" rather than the cooler fish room.

I keep 1 gal jugs of water in the freezer for emergency days but have yet to need them. (plan on just floating them in the 2 trout tanks to cool them off) Water temps are hovering at 70F and the trout have never been happier or growing faster. 2nd harvest about to take place as they are getting quite large.

I will also run the artesian well water (no pump needed) for an hour or so occasionally and that does wonders and costs us nothing. Been a very cool summer so far here in the southern mountains. Only been here for 3 summers but I would say that this is cooler than normal. Rarely hit 80F and here we are Aug 7.

I am planning on doing the exact same thing but with a 4'x6' PVC grid to maximize surface area contact. I will not know until next summer how well it works.

Daniel Budfuloski said:

Don't know if this would work (but it is what I plan on doing with my system when I get it up and running). I'm going to have a sump tank burried 4-6 feet down (where the temperature stays at a constant 50-55 degrees and has the effect of thermal cooling/heating) and have it pumped up to the surface of my fish tank that is burried half in the ground. Then i'm going to siphon the water off the bottom of my fish tank to the grow beds. My theory is... with constant 50-55 degree water pumped to the top of my fish tank and then being pulled to the bottom by the siphon effect, it will keep my whole tank the same tank year round. Do you guys think it will work?